JPS61281452A - Microwave discharge light source - Google Patents

Abstract

PURPOSE:To make the distribution of illuminance uniform, by providing a non- electrode discharge lamp, a part of the wall of which is flat, and by transmitting light from the lamp through a light-permeable member member to change the light into parallel rays through an external optical system to irradiate the rays upon a surface. CONSTITUTION:Microwaves from a magnetron 1 are introduced into a microwave cavity 5 through a waveguide 3 and an electricity supply port 8 so that a non-electrode discharge lamp 91, a part 91' of the wall of which is flat, emits light to the outside through a light-permeable member 71. The solid angle of the member 71 to a point on the lamp 91 is set at 2 steradian or less. The light is changed into parallel rays by a convex lens 14 located at the focal length from the flat part 91' of the lamp, so that the parallel rays are irradiated upon a surface 15. The light emitted by the lamp 91 is thus used effectively. Besides, the light is easily controlled to make the parallel rays and render the distribution of illuminance uniform.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a light source device that uses microwave discharge.

In particular, it concerns the effective use of the radiation source.

[Conventional technology]

FIG. 6 shows a conventional microwave discharge light source device disclosed in, for example, Japanese Patent Application No. 59-39980.

1 is a magnetron which is a microwave oscillator, 2 is a magnetron antenna, 3 is a waveguide, and 4 is a ventilation hole.

Reference numeral 5 denotes a cylindrical microwave resonant cavity, which has a light-transmitting member 7 on at least a part of its wall surface. The light-transmitting member 7 is made of an electrically continuous metal mesh V, and the sum of the solid angles extended from the lamp 901 point to the light-transmitting member 7 side is 2π steradians or more. Reference numeral 8 designates a power feeding port provided in a portion of the cavity wall 6 made of metal 9 connected to the waveguide 3 for feeding power from the microwave sound waveguide 3 to the microwave resonant cavity 5.

In addition, rare gas, mercury, etc. are sealed in the same part of the lamp 90, and the lamp 9 is made of Lv-shaped transparent material made of quartz glass. 10 is a lamp holder extending from the treatment of lamp 9;
It is also made from a dielectric material made of quartz glass, and is attached to the cavity wall 6 by a lamp set screw 101. Reference numeral 11 indicates a source reflecting plate that reflects the light emitted from the microwave resonance cavity 5, reference numeral 1) indicates a cooling fan that cools the magnetron 1 and the lamp 9, and reference numeral 13 indicates a box that houses the above-mentioned members.

Next, the operation of the above device will be explained. The microwaves oscillated by the magnetron 1 pass from the magnetron antenna 2 to the waveguide 3t, and these microwaves pass through the feed port 8 to the air 11I4 ship 6 and the metal mesh 4) to the optically transparent member 7 L. Power is supplied to the microwave resonant cavity 5 surrounded by the microwave. The rare gas in the lamp 9 is generated by this microwave, and this energy heats the tube wall of the lamp 9, and the enclosed mercury etc. evaporates and becomes gas, and the discharge causes metal gas such as mercury. The discharge is the main one, and it emits light in a spectrum depending on the type of gas. The light-transmitting swirling member 7 made of a metal mesh acts to reflect microwaves in the same way as metal, and only one component passes through the transparent member 7. Therefore, the source from the lamp 9 is radiated out from the microwave resonant cavity 5 and reflected by the source reflector 11 . The shape of the original reflecting plate 11 can be designed in various ways depending on the original use.

[Problem that the invention seeks to solve]

However, in the conventional microwave discharge light source device described above, the original reflection plate 11t is used as an optical system for controlling the light emitted from the microwave resonant cavity 5, and is used in semiconductor manufacturing processes. Ultraviolet exposure requires increasingly high-density patterning, and the lamp 9 is too large to control the light using the original reflector 11, which is a limitation.

The present invention has been made to solve the above-mentioned problems, and provides a microwave discharge source device that can effectively utilize the light emitted from a lamp and easily control the radiation source. The goal is money.

[Rounding method to solve problems]

The microwave discharge light source device according to the present invention has a part of the tube wall of the lamp in a planar shape, and a solid angle extending from one point of the lamp to the light-transmitting member side is 2π steradian or less, and The structure is such that the transparent member surface and the lamp absorbing surface face each other.

[For production]

In the present invention, since a part of the lamp wall is made flat, this flat part can be made smaller than the size of the lamp. It becomes possible to form an image on the irradiated surface, forming parallel light.

Original control such as uniform illuminance distribution and obtaining the desired irradiation area can be easily performed.

〔Example〕

Embodiments of the present invention will be described below with reference to all drawings.

In Fig. 1 and Fig. 2, 71 is a light-transmitting member provided at the top of the metal cavity wall 6 forming the cylindrical microwave cavity 111i35k, and the member 71 is electrically Advantageously, it consists of a continuous metal mesh and is made of the same material as the cavity wall 6. Further, the solid angle extending from one point of the cylindrical electrodeless discharge lamp 91 disposed in the microwave cavity 5 to the light-transmitting member 71 side is 2π steradians or less. A part of the wall surface of the lamp 91 is formed into a planar shape, and the peripheries of the top and bottom surfaces are curved, and the lamp 91 is disposed such that the planar portion 91' faces the surface of the light-transmitting member 71. Further, the height of the lamp 91 is smaller than its diameter. 41 and 42 are cut-off pipes that are provided on the microwave cavity wall 6 at right angles to the axis of the lamp 91 to cool the lamp 91, and allow all cold air to pass through without passing the microwaves.

1) and 1)' are a blower fan and an intake fan, respectively. Reference numeral 14 designates a convex lens disposed on the front surface of the light-transmitting member 71 as a focal point on the plane portion 91' of the lamp 91, and reference numeral 15 represents an irradiated surface on the front surface of the convex lens 14.

Next, the operation of the above device will be explained. First, the ti*microwaves oscillated by the magnetron 1 are generated by the magnetron antenna 2.
Power is supplied from the power supply port 8 to the microwave cavity 5 recessed by the microwave cavity wall 6 and the light-transmitting member 71 through the waveguide 3t. The microwaves cause the rare gas in the lamp 91 to discharge, and this energy heats the wall of the lamp 91, evaporating and gasifying the enclosed mercury, etc., and the discharge is mainly a discharge of metal gas such as mercury. , emits light with a spectrum depending on the type of gas. The light-transmitting member 71 is designed to reflect microwaves and transmit light. The source from the flat part 91' of the lamp 91 is the microwave sky []1ii
5 to the outside through the light-transmitting member 71t, the light is turned into parallel light by the convex lens 14 disposed at a focal distance from the plane portion 91', and is irradiated onto the irradiated surface 15. Depending on the size of the irradiated surface 15, the focal length and size of the external optical system and the size of the light-transmitting member 71 are appropriately selected. In order to further improve the parallelism of the emitted light to the outside, it is better that the area of the flat portion 91' of the lamp 91 is smaller, and the convex lens 14 should be used as much as possible in the center.

Also, in order to increase the original intensity, the irradiated surface 15 and the convex surface! :14 should be as close as possible.

Furthermore, the lamp 91 is cooled by blowing cold air from the side of the cylindrical lamp 91 in a direction perpendicular to the lamp axis, and by blowing air from the cut-off pipe 41 formed in the cavity wall 6 using the blower fan 1). The air is exhausted from a cut-off pipe 42 provided on the opposite side of the wall 6 to the intake fan 1)'. At this time, the airflow 16 flows along the wall surface of the lamp 91 formed with a flat planar part 91' or a curved part,
To efficiently cool the pupil of a lamp 91. In this way, it was decided to provide a manual device for completely cooling the lamp 91 from the direction perpendicular to the lamp axis of the cylindrical lamp 91 whose height is small in diameter and C.
The cooling effect can be improved, and damage to the lamp 91 due to overheating of the lamp 91 and deterioration of the lamp 91 can be prevented. Incidentally, instead of the cut-off pipes 41 and 42, it is also possible to use a mesh that does not transmit microwaves and allows only air to pass through. Further, in order to improve the parallelism of the light emitted through the convex lens 14, the circular surface of the wall 6 of the sky 111i1 other than the light-transmitting member 71 portion may be made of a material that absorbs light.

FIG. 3 shows a second embodiment of the present invention, in which a light-transmitting member 71 is provided on the side of the cavity wall 6.

Correspondingly, the lamp 91° convex lens 14 and the irradiated surface 15 are arranged in the same way as in the first embodiment, and it has the same functions and effects as the first embodiment.

Fig. 4 and Fig. 5 each show other embodiments of the electrodeless discharge lamp, and these examples also have flat portions 92' and 93' formed on part of the wall surfaces of the lamps 92 and 93, respectively. The size of the flat portions 92' and 93' can be made smaller than or equal to the size of the lamps 92 and 93, making it easier to control the light emitted from the microwave cavity 5 by an optical system disposed outside. That is, it becomes easier to form an image on the irradiated surface 15 and to create a parallel origin using the optical system outside the plane parts 92' and 93'.

〔Effect of the invention〕

As described above, according to the present invention, a lamp having a part of the lamp wall formed into a flat surface is arranged so that the flat part faces the surface of a light-transmitting member, and a desired size is determined by an optical system disposed outside. This has the effect of irradiating the irradiated surface of the lens with parallel light and obtaining a uniform illuminance distribution.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a device according to a first embodiment of the present invention, and FIGS. 2(a) and (b) are a front view and a bottom view of a lamp according to the first embodiment of the invention, respectively. , FIG. 3 is a bottom view of the device according to the second embodiment of the present invention, and FIG. 4(a), C
b) is a front view and bottom view of another embodiment of the lamp according to the present invention, and FIGS. 5(a) and (b) are a front view and a bottom view of still another embodiment of the lamp according to the invention, respectively. The bottom view and FIG. 6 are configuration diagrams of the conventional device. 1... Magnetron (microwave generation means), 3...
・Waveguide, 41.42...Iso to cutoff, 5・
...Microwave cavity, 6...Microwave cavity 1Ilii
J pupil, 71... Light transmitting member, 8... Power feeding port, 91
~93...electrodeless discharge lamp, 91'~93'...
Flat part, 1)...Blower fan, 1)'...Intake fan% 14...Convex lens, 15...Irradiated 1ffi%
1G...Airflow. Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (8)

[Claims] (1) A microwave generating means for generating microwaves, a microwave cavity to which the microwaves are fed through a waveguide and a power feeding port, and having a light-transmitting member on at least a part of the wall surface; In a device that includes a lamp disposed inside the microwave cavity and an optical system that controls the light emitted from the microwave cavity, the solid angle extending from one point of the lamp to the light-transmitting member side is 2π. What is claimed is: 1. A microwave discharge light source device characterized in that the lamp wall is made to be less than steradian, a part of the lamp wall is flat, and the light-transmitting member surface and the flat part of the lamp wall are opposed to each other. (2) The microwave discharge light source device according to claim 1, wherein the microwave cavity is cylindrical. (3) The microwave discharge light source device according to claim 2, wherein the top of the microwave cavity wall is formed of the light-transmitting member. (4) The microwave discharge light source device according to claim 2, wherein a side portion of the microwave cavity wall is formed of the light-transmitting member. (5) The microwave discharge light source device according to any one of claims 1 to 4, wherein the lamp has a cylindrical shape whose height is smaller than its diameter. (6) The microwave discharge light source device according to claim 5, wherein the cylindrical lamp is curved at least around its top and bottom surfaces. (7) The microwave cavity wall is provided with means for blowing cooling air toward the lamp from a direction perpendicular to the axis of the cylindrical lamp. Microwave discharge light source device. (8) The microwave discharge light source device according to any one of claims 1 to 7, wherein the optical system is a convex lens disposed at a focal distance from a flat surface of the lamp wall. .